I'm aware that Mao believed that. That's why the narrative that Deng Xiaoping "backstabbed" socialism is false, Reform & Opening Up was a continuation of the economic basis laid out by Mao.
As for cracking down on flaunting wealth, if your impression is already highly skeptical of China, it can seem that it's only to hide it from the public. A more comprehensive view of China, however, reveals it to not be mere rhetoric but the outcome of having both a socialist state and the contradictions rising from marketization.